o-Tolidine
Description
o-Tolidine (CAS 119-93-7), also known commercially as 3,3'-dimethylbenzidine or DMB, is an aromatic diamine used as a chemical intermediate in the production of dyes, pigments, and curing agents.
Its bifunctional amine structure makes it a reactive building block for synthesizing azo colorants and polyurea-based systems across several industrial sectors. In the dye and pigment industry, it is a key intermediate.
This chemical is essential for manufacturing diazo-based yellow and orange pigments used in printing inks and packaging colorants. Textile and leather processors use DMB-derived dyes to achieve high-fastness coloration.
These dyes are effective on both natural and synthetic substrates. In polymer and elastomer manufacturing, it functions as a curing agent for polyurethane and polyurea systems where controlled crosslink density is required.
Specialty coatings formulators also source it as a precursor for producing performance pigments with strong lightfastness characteristics. This ensures long-lasting color stability in various industrial coating applications.
The product is supplied as a solid, typically in flake or crystalline powder form. Technical grade is the standard commercial specification for industrial intermediate applications and large-scale manufacturing.
It is available in bulk quantities suited to pigment manufacturers and polymer processors. Packaging options range from drums to bulk bags depending on specific volume requirements and logistical needs of the client.
Physical Properties
| Melting Point | 129-131 °C |
| Boiling Point | 300 °C |
| Density | 1.234 g/cm³ |
| Flash Point | 244 °C |
| Appearance | o-Tolidine is a white to reddish crystal or powder. Darkens on exposure to air. Often used in paste or wet cake form. Used as a basis for many dyes. |
| Color | light brown |
| Form | powder (may contain lumps) |
| Water Solubility | Slightly soluble in water. |
| Refractive Index | n 20/D 1.341 |
Safety & Handling (Learn More)
Trade & Regulatory
| HS Code | 29215900 |
| UN Number | 3082 |
| ADR Class | 9 |
| Packing Group | III |
| Storage Class | 6.1C - Combustible acute toxic Cat.3 toxic compounds or compounds which causing chronic effects |
| WGK (Germany) | 3 |
Documentation
Other Names
3,3'-dimethylbenzidine|4-(4-amino-3-methylphenyl)-2-methylaniline|DMB
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